- Etch for 20-30 s with 37% phosphoric acid,
- Wash and dry the surface maintaining isolation,
- Apply the resin,
- Cure,
- Check for adequacy.
Isolation is critical to successful sealant application. Operator and assistant must act
as a team as it is impossible for single operators to apply sealant effectively. The vast
majority of trials have demonstrated cotton wool and suction to be an effective means
of isolation. Rubber dam is advocated by some because of the superior isolation
offered by this material. This is probably true but its use is frequently not possible
because of the stage of eruption of the tooth or level of co-operation of the patient. It
would be inappropriate to delay sealant application to allow further eruption to permit
the application of rubber dam. The application of sealant is a relatively non-invasive
technique, frequently used to acclimatize a patient. It is difficult to justify the use of
rubber dam with the associated use of local anaesthetic and clamps for the majority of
patients, on both clinical and economic grounds.
Glass ionomers have also been used as sealants, the application technique is less
sensitive, than that for resins. Unfortunately glass ionomer sealants have poor
retention. It is suggested that the fluoride release from glass ionomers provides
additional protection but the clinical relevance of this remains doubtful. The addition
of fluoride to resin sealants has been demonstrated to provide no additional benefit.
Glass ionomer sealants only have a place as temporary sealants during tooth eruption,
when adequate isolation to permit the application of resin is not possible or in patients
whose level of anxiety or co-operation similarly prevent placement of resin. Glass
ionomers have been developed specifically for this role but clinical evidence of their
effectiveness is not yet available.
Key Points
Application of glass ionomer sealants
- Clean the surface
- Isolate the tooth
- Run the glass ionomer into the fissures
- Protect the material during initial setting
- Apply unfilled resin, petroleum jelly, or fluoride varnish to protect the material.
For anxious patients application can be done with a gloved finger until the material is
set.
Resin fissure sealants are effective; a recent systematic review has demonstrated 57%
caries reductions at 4 years, with retention of 71-85% at 2 years falling to 52% at 4
years (Ahovuo-Saloranta et al., 2004). To gain the full caries preventive benefit
sealants should be maintained, that is, sealants with less than optimal coverage
identified and additional resin applied.
Since the development of sealants there has been a question regarding the effect of
sealing over caries, the concern being that caries will progress unidentified under the
sealant. Given the difficulty in diagnosing caries this must be a frequent occurrence in
daily practice. A number of trials have examined this by actively sealing over caries,